Fiber optics cables, often carrying two fibers each, do not have the intrinsic strength found in electrical cables and, so, must be carried in raceways or other channel members rather than being strung using standard wire hangers. These raceways are sometimes installed beneath raised flooring. In order to install them in different locations, the installer either has to carry a wide variety of lengths or cut them to the desired length on location. My invention obviates this difficulty and yet provides a strong and stable raceway structure.